This invention applies to the field of bi-pin lamp sockets, and in particular, those lamp sockets for high-temperature, high current lamp, such as quartz-halogen lamps. Bi-pin halogen lamps normally operate at very high temperatures in order to maintain the halogen transfer cycle that keeps the filaments from evaporating and depositing on the quartz bulb. It is common for such lamps to be operated at the highest possible current to produce high color temperatures required for display fixtures, instruments and projectors. This results in high pin seal temperatures.
It is well known in the industry that the life of a halogen lamp is inversely proportional to the pin seal temperature. The hotter the seals, the shorter the tamp life. It is also well known that lamp socket failures are usually caused by the overheating. The lamp pins are heated by the filament and they transfer heat to the socket receptacles. The receptacles become annealed and lose contact with the lamp pins, creating resistance and arcing. The contact resistance and arcing cause both the socket and the lamp to be further heated. The cycle of increasing contact resistance continues until failure of socket or the lamp pin seals (or more often both) occurs.
There are bi-pin sockets currently available, in which generally cylindrical ceramic housings hold female receptacles. A ring of finned heat radiator material is frictionally engaged onto the exterior of the ceramic housing. The principal disadvantages of these prior art devices is that the pin receptacles are not in intimate thermal contact with the housings, and the housings are so thick between the receptacles and the radiator that they are relatively ineffective heat transfer paths for reducing lamp pin temperatures. Therefore, they are still subject to characteristic arcing failures.
The disadvantages of the prior art sockets are overcome by achieving the primary purposes of the present invention: to reduce lamp pin seal temperatures; to maintain good contact between the lamp pins and socket receptacles; and to prevent resistance build-up and contact arcing.